Algebra help!!

Question

football team has a 5 gallon water jug.  Before each practice, Trevor is in charge of filling it up.  At any given time, how many gallons, g, will Trevor have to pour into the water jug given the fraction of the water jug, w, already filled?
a
g=5/w

 
b

 g=5-5w
c
g=5w
 
d

g=5-5/w

Answer 1

Start by considering that if the water jug was empty, you would have to fill it with 5 gallons, and so the amount you would have to fill is 5 gallons minus however many gallons are already in the water jug. So if the one water jug is a fraction w full, and the water jug can hold up to 5 gallons, then the water jug has 5*w gallons in it already. Then you would need to fill it with 5-5w gallons, so the answer is b.